1. Field of the Invention
This invention relates to a bogie truck car body support system without a swing bolster, wherein a car body is supported on a truck frame through bolster springs accommodating horizontal displacements of the car body and a track and transmission of forces longitudinally of the car body is effected by linking means accommodating vertical and horizontal displacements of the car body and truck.
2. Description of the Prior Art
A prior art truck type car body support systems will be described by referring to FIGS. 1-4. As shown, the numeral 1 designates an axle having an axle box 2 mounted at either end thereof. A truck frame 4 is supported on the axle boxes 2 of the axle 1 through axle springs 3. The numeral 5 designates an air spring constituting a bolster spring of low transverse rigidity. A car body 6 is supportedd on the truck frame 4 through the air springs 5. A center pin 7 is connected at its upper end to the undersurface of the car body 6 in a position which corresponds to the center of the truck frame 4 and inserted at its lower end in the truck frame 4. A rubber stopper 8 is mounted on the edge of an opening formed in the truck frame 4 for receiving the center pin 7, to support the car body 6 through the center pin 7 when there are relatively large transverse displacements between the truck and the car body 6. A link 9, provided at opposite ends with rubber bushes 10, is connected at one end to a center pin support 11 through the rubber bush 10 and at the other end to a link support 15 through the rubber bush 10. The center pin support 11 is fitted over the center pin 7 through a bush 16, and the link support 15 is attached to the underside of the truck frame 4. Rotary movement between the truck and car body 6 is accommodated by a sliding section between the bush 16 and center pin 7. The numeral 12 designates a holding member for supporting the bush 16 for rotation relative to the center pin 7, the holding member 12 being mounted on the center pin 7 through a nut 13 fitted on a bolt at the lower end of the center pin 7.
In the aforesaid construction, longitudinally acting forces acting on the center pin 7 at acceleration and deceleration are transmitted to the truck frame 4 through the center pin supports 11, rubber bushes 10, links 9 and link supports 15. At this time, the car body 6 and truck vibrate back and forth and are relatively displaced both vertically and transversely, causing the links 9 to be inclined. However, the pinching movement of the links 9 is absorbed by the bushes 10. Rotary movements of the car body 6 and the truck are accommodated by rotary movements of the center pin 7 and the center pin supports 11.
Some disadvantages are associated with the aforesaid construction. For example, since rotary movements of the center pin 7 and center pin supports 11 are accommodated by sliding movement of the center pin 7 with respect to the bush 16, there is a slight clearance between the center pin 7 and bush 16. Thus the center pin 7 wobbles in the clearance when the center pin supports 11 vibrate during traveling movement of the car body 6 and unpleasant noise is produced as the vibration is transmitted through the center pin 7 to the car body 6, thereby reducing the riding comfort of passengers.
Proposals have been made to minimize the clearance between the center pin 7 and bush 16 and to use a rubber bush for the bush 16 to prevent the center pin 7 from wobbling. However, wear is caused on the center pin and bush with year and wobbling is inevitable. In addition, the use of a rubber bush suffers the disadvantages that the construction becomes complex and difficulties are experienced in assembling and disassembling the car body 6 and truck.